Heating and radiating unit for electrical heaters

ABSTRACT

An electric heating element for baseboard heaters or the like wherein strips of supporting material, insulating strips and a heater element strip are fed to a forming and gathering apparatus and formed into a heating unit. The supporting material preferably has fins stamped thereon.

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ABSTRACT: An electric heating element for baseboard heaters or the likewherein strips of supporting material, insulating strips and a heaterelement strip are fed to a forming and gathering apparatus and formed 501, 01. M538 35 9. 9 1 h 2 02 1 4" 6 a m1 NW Tum 71 2 u n uulz "0 u "08 4n "71 B m m m9 "5 .l u "6 2 7mm 5 6 nm 3 5 u w m m ""5 m d mm nqmo m 4 51 m d MM IF 1.] 0 55 [.1

into a heating unit. The supthereon.

[56] References Cited UNITED STATES PATENTS I i/1961 Browne...

porting material preferably has fins stamped PATENTED JA! 4 H72 SHEET 1OF 2 F I G 5 INVEIRITOR HARLEY J. ORR

ATTORNEYS ales-$21987 PATENTED JAN 4 i972 sum 2 0F 2 HEATING ANDRADIATING UNIT FOR ELECTRICAL HEATERS This invention relates toconvection heaters and more particularly to electric heaters of the wallor baseboard type.

Heaters of this type are well known in the heating art but, in general,have radiating fins so attached to the sheath member as to produce noiseand poor heat transfer.

One of the objects of the present invention is to provide a heating unitfor a baseboard or wall type of heater which is simple and inexpensivein its method of manufacture.

A further object of the invention is to provide a heating unit for wallor baseboard type of electric heaters which is made from strip materialand in which the radiating fins are integrally attached to the sheathcontaining the heating element.

A further object is to provide a heating unit in which the heatingelement, sheath and radiating fins comprise one unitary, composite,striplike member easily installed and economically manufactured.

In one aspect of the invention, the wall or baseboard heater compriseselongated housing members enclosing a wireway, a heat-deflecting baffle,and a heating and radiating member suspended by hangers or the like. Theheating and radiating member comprises a composite unitary stripcomposed of two strips or sheets of aluminum or suitable material havingfins formed therefrom and having a heating element with mica or similarinsulating material on each side thereof contained within the aluminumsheets. The entire composite strip is preferably formed in a simple,automatic operation in the which strips of thin metal such as aluminum,strips of thin insulating material such as mica, and a preformed heatingelement are fed to forming and edge-bending dies to provide thecomposite strip. The invention also can be practiced without fins.

As a second aspect of the invention, the composite heater and fin stripmay comprise a single strand of preformed heater resistance wire ormaterial extending longitudinally of the strip, or it may comprise amultiple strand of resistance wire extending through the upper portionof the strip and bent backwardly to extend through the lower portion ofthe strip. The strip may or may not be sealed against entrance ofmoisture at each end thereof.

As a third aspect of the invention, a third strip of aluminum orsuitable metallic material may be interposed between one of the stampedmetallic strips and its adjacent insulating strip, or such a strip maybe positioned between each of the outer stamped sheets and its adjacentinsulating strip.

The above and other objects, advantages and features of the inventionwill become apparent from the following description taken in conjunctionwith the accompanying drawings which illustrate exemplary embodiments ofthe invention.

In the drawings:

FIG. 1 schematically illustrates the type of heater in which the unitaryheating and fin assembly of the invention may be utilized;

FIG, 2 is a perspective view of the unitary and composite heater and finunit;

FIG. 3 is an elevational view of the unit of FIG. 2;

FIG. 4 is a cross-sectional view taken on the line 4-4 of FIG. 3;

FIG. 5 is a view similar to FIG. 3 but illustrating a modified form ofthe heating element; and

FIG. 6 illustrates the method for forming the composite or unitaryheating and fin strip of FIG. 2;

referring to the drawings and more particularly to FIG. I, there isshown a housing 10 comprising a back plate 11 adapted to attach thebaseboard to a wall, a wireway 12, a deflector plate 13, a grille orscreen guard 14, a front member 15, and a heating and radiating unit ormember 16. Electric wiring for the heating element is adapted to extendthrough the wireway 12 and connect with the leads 17 (FIGS. 2, 3 and 5)of the heating element. Suitable thermostatic and fail safe controlelements (not shown) may also be incorporated in the housing 10 in awell-known manner.

As more particularly shown in FIGS. 2 to 4, the heating and radiatingunit or member 16 comprises a unitary composite strip formed from twosheets 18 and 19 of aluminum or the like encompassing a pair of stripsor sheets 20 of mica or similar insulating material overlying apreformed heating element 21. The strips 18 and 19 are stamped orpressed to form the fins 22, the fins of one strip extending in onedirection and those of the other in the opposite direction, asillustrated in FIGS. 2 and 4. If desired, a third sheet or strip ofaluminum 19A (dashed lines, FIG. 6) may extend between the sheet 19 andits associated mica strip 20 to protect the insulating strip 20 at theopenings 23 from which the fins 22 are punched. The aluminum sheet orstrip 18 is wider than the strip 19 to provide upper and lower portionsadapted to be folded or crimped as shown at 24in FIGS. 2 to 4 to clampor secure the heating and radiating unit 16 into one unitary compositestrip or structure. The heating element 21 preferably comprises awirelike resistance preformed into a relatively flat, open loop orcyclelike formation as shown in FIGS. 3, 4 and 5.

In FIGS. 2 to 4, the open loop or cyclelike resistance wire or heatingelement 21 extends through the upper portion of the heating unit 16 andthen bends backwardly to extend through the lower portion of the heatingunit. Depending upon the heating wattage desired, however, the heatingelement or resistance wire 21 may comprise a single or multiple strandextending continuously through the unit 16 and having terminals at eachend thereof as illustrated in FIG. 5. The ends of the unitary heatingand radiating unit 16 may also, if desired, be sealed against theentrance of moisture by a suitable silicon or ceramic compound. As isalso known in the wall or baseboard heating art, there is a tendency forheat to concentrate in the central portion of the heating unit. To avoidthis, the invention also contemplates the spreading of the convolutionsof the open loop or cyclelike heating element 21 to provide a greaterdensity of heat at the ends of the unit 16.

In FIG. 6 there is illustrated a method for the automatic, simple andeconomical forming of the composite and unitary strip or heating unit16. Referring to FIG. 6, sheets or strips 18 and 19 in roll forms 30 and31 are fed to fin-stamping apparatus or dies 32 wherein the fins 22 areformed from the relatively thin sheets of metallic or suitable material.The formed strips are then fed to a composite strip forming or gatheringapparatus or element 33. Also fed to the gathering apparatus 33 fromrolls 34 or the like are two sheets or strips 20 of mica or insulatingmaterial and a strip of electrical resistance or heating wire 21supplied from a coil 35 and preformed by apparatus such as dies 36 intoa substantially flat open loop or cyclelike formation as shown in FIGS.3 and 5. The outer portions of the wider strip 18 are then folded orcrimped around the strips 19, 20 and 21 by a suitable forming apparatusor dies 37 to provide a unitary composite heating and radiating strip orunit assembly 16. Thereafter the composite strip is cut intopredetermined lengths and the cut ends may be sealed against entrance ofmoisture by a suitable silicon compound or the like. Also, the terminalleads 17 are attached. If a third metallic strip is desired between oneof the finned strips and an insulating strip, as above described, itwould be fed to the gathering apparatus 33 from a roll of the stripmaterial (not shown).

The heating element may be of resistance wire, graphite deposit oninsulating material, or a printed circuit type element. Also, the finsmay be omitted and the element sheath may be metallic or insulatingmaterial.

What is claimed is:

I. A unitary composite striplike heating unit for baseboard or likeelectric heaters comprising at least two strips of relatively thinmetallic material each having a plurality ofintegral continuousradiating fins stamped to extend laterally outward from one face of eachstrip generally throughout the entire width of said strip so as toexpose substantially the entire areas thereof, two relatively thinstrips of insulating material positioned between said metallic stripsadjacent the inner surfaces thereof, a wirelike electric heating elementpositioned between said insulating strips and extending along the lengthof said strips, the upper and lower edges of one of said metallic stripsbeing folded over the outer face of the other of said metallic stripsthroughout substantially its entire length tightly to clamp saidinsulating strips and said heating element within said metallic strips,and sealing means at the ends of the striplike heating unit to guardagainst entrance of moisture.

2. In a heating unit according to claim 1 wherein said heating elementis of substantially flat open loop cyclelike formation, with saidformations being closer spaced toward the ends strip of metallicmaterial is positioned between one of said metallic strips and oneofsaid insulating strips.

4. In a heating unit according to claim 1 wherein the compositestriplike heating unit is of predetermined length, and the sealing meansis a compound.

UNITED STATES PATENT OFFICE (IRTIFICATE 0F CORECTION Patent No. 3 ,632,987 Dated January 1972 Invent0r(s) Harley J. 0561' It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Patent front page, [73], insert --Sola. Basic Industries, Inc.,Milwaukee, Wisconsin"; Patent front page, [60], insert -Division ofSerial No. 666,063, filed September 7, 1967, now Patent No. 3,510,940,issued May 12, 1970.

Signed and sealed this 21st day of November 1972.

(SEAL) Attest:

EDWARD M.FLE CHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents PC4050 (10-69) USCOMM-DC 60375-P69 n U.S, GOVERJMENT PRINTINGUFFICE 1969 O'366-j34 ENTTEE STATES PATENT oEETEE @ERNNCATE F CORREQHONPatent No. 3 632,987 Dated January 1- 1 1972 Inventor(s) Harley J. Orr

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Patent front page, [73], insert --Sola Basic Industries, Inc..,Milwaukee, -Wisconsin--5 Patent front page, [60], insert --Division ofSerial No. 666,063, filed September 7 1967, now Patent No. 3,510,940,issued May 12, 1970.

Signed and sealed this 21st day of November 1972.

(SEAL) Attest:

EDWARD MQFLETCHERJR. ROBERT GOTISCHALK Attesting Officer Commissioner ofPatents FORM PO-IOSO (10-69) USCOMM DC 6O376 P69 n us. sovzwwzm'PRINTING DFFICE 1959 o-3se-ua UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3 ,632 ,987 Dated January L 19T2 Inventor(s)Harley J. oer]? It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Patent front page, [73], insert -Sola Basic Industries, Inc., Milwaukee,Wisconsin--5 Patent front page, [60]., insert --Division of Serial No.666,063, filed September 7', 1967, now Patent No. 3,510,9MO, issued May12, 1970.

Signed and sealed this 21st day of November 1972.

(SEAL) Attest:

EDWARD mmmgmsmm. ROBERT GOTTSCHALK Attesting Offlcer- Commissioner ofPatents FORM PO-105O (10-69) USCOMM-DC 6O376-P69 U.S. GOVERNMENTPRINTING OFFICE: I569 0-366-534

1. A unitary composite striplike heating unit for baseboard or likeelectric heaters comprising at least two strips of relatively thinmetallic material each having a plurality of integral continuousradiating fins stamped to extend laterally outward from one face of eachstrip generally throughout the entire width of said strip so as toexpose substantially the entire areas thereof, two relatively thinstrips of insulating material positioned between said metallic stripsadjacent the inner surfaces thereof, a wirelike electric heating elementpositioned between said insulating strips and extending along the lengthof said strips, the upper and lower edges of one of said metallic stripsbeing folded over the outer face of the other of said metallic stripsthroughout substantially its entire length tightly to clamp saidinsulating strips and said heating element within said metallic strips,and sealing means at the ends of the striplike heating unit to guardagainst entrance of moisture.
 2. In a heating unit according to claim 1wherein said heating element is of substantially flat open loopcyclelike formation, with said formations being closer spaced toward theends of said heater unit to distribute heat more evenly along the lengthof the unit.
 3. In a heating unit according to claim 1 wherein a thirdthin strip of metallic material is positioned between one of saidmetallic strips and one of said insulating strips.
 4. In a heating unitaccording to claim 1 wherein the composite striplike heating unit is ofpredetermined length, and the sealing means is a compound.